I'm working on my own unattended vista,  I am attempting to make a version that i can use to perform re-installations on my computer and on many others (I do a lot of freelance PC-repair) and I have integrated hundreds of drivers, the driver signing holdup is unacceptable.  At the moment, I use wpi to open a self extracting .rar to put them where I can at least use them.  I considered making the drivers into an .ISO, and using daemontools lite + daemonscript (which I have already integrated) to auto-mount the ISO at install, therefore making "have disk" option much easier for drivers.